Auto transmission swap

Sorry G-Man...thought you were offering a source. Lokar has longer cables, so does B&M, so does the local boat supply. Shifter came with a 4 foot cable - not long enough but still don' know the length I need yet. Will keep you posted.

new question to revive this awesome thread. i just got a (used) 700r4 from an '89 van for a song and a dance. i already have a turbo 350 tranny installed and working that i will remove to put in the 700r4. i know i need to modify my hanger and shorten the drive shaft. my shift lever is just the stock 3-on-tree slightly modified to work as an auto shift. so...
my question is, what else do i need to look into? (excuse my limited mechanic skills and terms) will i have to modify the "vacuum lines" that are connected to turbo350 at all? will i need to look into a new "kickdown cable"? and lastly, where do i find out about the electrical plug on the tranny? it looks like a 4 post terminal and does it hookup to anything or do i just buy a wiring kit that deadends that circuit? in other words, what do i do with that?
james

You need a "on computer" box for the trans. You can get it at any speed shop or online at Summit or Speedway motors.

Heres one trans kit

I think there is a more economical way to do that with a toggle switch, but I have to find more out on it yet.

billski wrote:I will need a longer cable. Haven't determined what length yet. I will let you know. Do you have a special source?

I used a 8' B&M cable for my 350 turbo...Fit perfect...any shorter would not of worked.

oh yeah, and can i use the same torque converter (i think thats what its called) that is on there now? i didnt know if they differ from turbo350 to 700r4...

Well my van is finally in the hands of the mechanic who is doing the trans swap - we're doing a swap. I rebuilt his shed, he's doing the swap with all parts and labor included, except for the shifter. So far he took out the 3-tree and installed the 200-4R, and as I type he's fabricating the trans mount. Going to see it later today. Getting anxious! Hopefully another week I'd it will be on the road. I post some pics eventually, including a shot of my Lokar shifter.

[quote="donivan65"]Transmissions are not going to help,,,,whether they are a 2, 3, 5, or 27 speed, high gear is always 1 to 1, the only exception is if you get an overdrive one, which will drop it down in high gear to about .70 to 1. The real solution is the rear end, which there are at least 4 choices. The 3:08 and 3:36 let the engine turn slower for any given speed. And rule #4 is a guy needs to drain his differential, check his axles and see what gear ratio he has so he knows what he got. As a matter of fact, I unloaded the TreeVan differential today to see what I got and if it will be better than what is in my van right now,,,,,,,,,

I have to disagree, to a certain extent, with Donivan - - the 700R makes ahuge difference when operating in OD. With the .70 final drive gear ratio and lock-up converter the engine RPM/s will drop 900 - 1100 RPMs.

My '67 is running 3.73 rear gears, 28.5" tall tires, when it is running 65 mph the engine is running 2000 rpms - - which is just about perfect for a brick shaped vehicle.

With the same set-up running 3.08 gears the engine RPM would be 1700 at 65 mph - -which is way to low for aerodynamics of our vans.

if you would like to work out combinations, check out - - http://www.angelfire.com/fl/procrastination/rear.html

There is a reason I do not weigh in on many discussions, whether it's on this great site or vcvc. The type of back to back replies to my thoughts is the reason why.

To answer your question the 700R is "my" transmission of choice for most GM applications. With its super low first gear and OD final drive it is a winner at both ends.

The first good news is the 3.06 first gear will help a the van pulling our, especially when towing.

The OD with lock-up converter will drop RPMs by 1000. So running a 700R a 3.73 gear and "stock" van tires with an outside diameter of 25.5" the engine will be turning 2500 RPMs at 72 MPH. With the stock 1:1 transmission output the same van will be running 51 MPH at 2500 RPMs.

Running a 700R in a van with a good running stock 194, 230 or 250 should be able to push a brick shaped van through the air at 65 MPG while turning 2250 RPMs.

Just as an FYI, I do not sell myself as an expert . . . just someone with a lot of experience - - - 50 years of working on all types of vehicles, a GM trained auto tech, 25 years teaching high school Auto tech and an ASE Master technician. All that said whatever I offer is just an opinion.

joyrde your opinions are very welcome, what better infor than from a GM tech. Your weighting in is good timing for me as I was on the fence to which to go with 200r4 or 700r4 for the 64.

I wanna swap my non-overdrive transmission out with one With Overdrive!!! Like a turbo 350 or 400?? Power Glide would be nice.
How do I adjust the brake pedal rod?? Just replaced entire system....

boy did i come on the right day !! I was just about to ask the same thing al,ost . I want to rebuild a rear for my 64 because the old one works but it seems to have lots of backlash I wasn't sure what gears to but in it so now i'm thinking about a set of 308s .. The thing is now how hard might it be to find a set for a 64 axle ?? were would be a good place to start ??
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Im seeing a 12 bolt rear end? You might have to go shopping to find a smaller ratio for it. Im thinking from what Ive learned here is a 12 bolt in the vans might only be a 3:73 or a 4:11 ?

I think mine has a 12 bolt also, maybe thats why it dont go so fast. As far as I can tell, the speedo doesnt work yet.

I sat down with a pot of coffee and a calculator one morning and came up with 2250 rpm @ 60 mph in OD with a 700R with the 4:11's, if it was gonna be a daily driver Id definatley be thinkin of changin ratios. Also I started collecting some parts for the lock up on the 700 today, scrounged a kick out switch for the brakes and got a 4 pin plug ( my trans is a 1982) need to order a vacumn switch that should run about 40$, sounds like a simple thing to do, only need 1 wire to the trans.

After getting stuff around for the converter lock-up, that Painless system isnt looking to bad, in theory you could run the lock up manually with a simple switch but I dont see that as practical at all. I have been layin' under the van looking at our long brake lever trying to figure out a way to rig up another brake switch to it (like the painless kit supplies) or if there is a switch available that could tap into the brake system? Has anyone already done this ?

I have the 7ooR4 with a 3:23 rear gear and the tire rolling high is 24.4", The tire measures 26" unloaded and the axle stands 12 off the ground loaded, when rolling, the tire is subject to centrifical force and becaomes 24.4" rolling high.

At 50 MPH in fourth gear TCC engaged my engine turns 1850 RPM

M1D

Digs: I did the $12 brake switch, easy. Its a popular switch from any parts place. a spring loaded push button to on with a wether sealed button. wired right into the power wire from a 10 amp fuse going to the TCC solinoid.

It breakes the power when you just touch the brake pedal so the TCC disengages,
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You just drill one hole. It stands only 3/4" high on the inside so its not in the way.


Out side I located it so the brake arm pushes the brake light switch lever against it. That way the TCC disemgages at the same time the brake lights come on.



Make sure the brake pedal return spring is tight enough to return the pedal and click the switches.


works great, I can touch the brake pedal while driving to hear and see on the Tach if the clutch disengages and re-engages when I let the brake pedal back up.

M1D